11. Ionic Liquid Pretreatment: Mechanism, Performance, and Challenges

  1. Charles E. Wyman3,4
  1. Seema Singh1,2 and
  2. Blake A. Simmons1,2

Published Online: 5 APR 2013

DOI: 10.1002/9780470975831.ch11

Aqueous Pretreatment of Plant Biomass for Biological and Chemical Conversion to Fuels and Chemicals

Aqueous Pretreatment of Plant Biomass for Biological and Chemical Conversion to Fuels and Chemicals

How to Cite

Singh, S. and Simmons, B. A. (2013) Ionic Liquid Pretreatment: Mechanism, Performance, and Challenges, in Aqueous Pretreatment of Plant Biomass for Biological and Chemical Conversion to Fuels and Chemicals (ed C. E. Wyman), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9780470975831.ch11

Editor Information

  1. 3

    Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, University of California, Riverside, USA

  2. 4

    BioEnergy Science Center, Oak Ridge, USA

Author Information

  1. 1

    Deconstruction Division, Joint BioEnergy Institute, Emeryville, USA

  2. 2

    Biological and Materials Science Center, Sandia National Laboratories, Livermore, USA

Publication History

  1. Published Online: 5 APR 2013
  2. Published Print: 10 MAY 2013

Book Series:

  1. Wiley Series in Renewable Resources

Book Series Editors:

  1. Christian V. Stevens

Series Editor Information

  1. Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium

ISBN Information

Print ISBN: 9780470972021

Online ISBN: 9780470975831

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Keywords:

  • biomass recalcitrance;
  • cellulose crystallinity;
  • ionic liquids;
  • ionic liquid pretreatment;
  • lignin

Summary

Ionic liquids are of increasing interest to the biofuels community due to their properties as a means of effectively pretreating biomass. Ionic liquids (ILs) are composed of anions and cations and typically have melting temperatures below 100 °C. There have been several classes of ionic liquids, in particular those belonging to the imidazolium family, that have been demonstrated to be very efficient in pretreating a wide range of lignocellulosic materials. There are over a thousand ILs that have been categorized in various databases, but only approximately 25 ILs are known to be effective biomass solvents; the majority of these are based on the imidazolium class of cations. There is undoubtedly a large amount of knowledge yet to be discovered in terms of anion-cation pairing and screening before an optimal and commercially viable IL pretreatment technology solution is realized. IL pretreatment has been shown to decrease the lignin content and cellulose crystallinity of lignocellulose and generates a material that is, depending on the specific pretreatment conditions used, readily saccharified into fermentable sugars. There are a number of IL pretreatment process routes under investigation that further define the desired task-specific properties of the ILs used. This chapter gives an overview of the various ILs and respective pretreatment technologies under development, in addition to describing the underlying mechanisms of how ILs interact with biomass and its components to overcome biomass recalcitrance.